Hydrolyzed chlorosilicon by-product addition to cement

Abstract

The present invention is an improved process for preparing a portland cement composition where the process comprises heat calcining a mixture comprising a source of calcium and a source of silicon to form clinker. The improvement comprises providing to the process a silicon containing product resulting from the hydrolysis of chlorosilicon by-product as at least a portion of the source of silicon.

We claim: 
     
       1. In a process for preparing a portland cement composition where the process comprises heating a mixture comprising a source of calcium and a source of silicon, the improvement comprising providing to the process a silicon containing product resulting from the hydrolysis of chlorosilicon by-product as at least a portion of the source of silicon. 
     
     
       2. A process according to claim 1, where the mixture comprising the source of calcium and the source of silicon further comprises a source of aluminum and a source of iron. 
     
     
       3. A process according to claim 2, where the mixture comprises limestone, clay, silicon dioxide, and aluminum oxide and an iron oxide. 
     
     
       4. A process according to claim 1, where the source of silicon comprises 25 weight percent to 100 weight percent of the silicon containing product. 
     
     
       5. A process according to claim 1, where the chlorosilicon by-product is from a process for reacting silicon metalloid with hydrogen chloride to form chlorosilanes. 
     
     
       6. A process according to claim 1, where the chlorosilicon by-product is from the reaction of an organochloride with silicon metalloid to form organochlorosilanes. 
     
     
       7. A process according to claim 1, where the chlorosilicon by-product has an SiCl functionality greater than or equal to 2.8. 
     
     
       8. A process according to claim 1, where the silicon containing product is formed by contact of the chlorosilane by-product with water. 
     
     
       9. A process according to claim 1, where the silicon containing product is formed by contact of the chlorosilane by-product with an aqueous slurry of calcium oxide. 
     
     
       10. A process according to claim 1, where the silicon containing product is washed with water to reduce the chloride content of the silicon containing product. 
     
     
       11. A process for preparing clinker suitable for use in a portland cement composition, the process comprising heat calcining a mixture comprising an oxide of calcium, an oxide of aluminum, an oxide of iron, and oxide of silicon, and a silicon containing product resulting from the hydrolysis of chlorosilicon by-product, where the silicon containing product comprises about three weight percent to 100 weight percent of silicon added to the process. 
     
     
       12. A process according to claim 1, where the silicon containing product is formed by contact of the chlorosilicon by-product with aqueous hydrogen chloride. 
     
     
       13. A process according to claim 1, where chloride present in the silicon containing product extracts alkali deposits from a cement kiln to produce a low-alkaline clinker. 
     
     
       14. In a process for preparing a portland cement composition where the process comprises heating a mixture comprising a source of calcium and a source of silicon, the improvement comprising providing to the process as a source of silicon a silicon containing product resulting from the hydrolysis of chlorosilicon by-product where the silicon containing product comprises about three weight percent to 100 weight percent of silicon added to the process.